I am rated around 1600 and I am trying to expand my opening knowledge
of the Ruy Lopez. My question relates to the pawns in front of a
castled king. The general advice I usually see is that you shouldn't
move these pawns because it necessarily creates weaknesses in front of
the king. However, there are many openings where these pawns are moved,
but in most cases there is a fianchettoed bishop to take the place of
the pawn.

Specifically, I wonder why White plays h3 in different variations of
the Ruy Lopez. It seems that h3 is necessary to prevent Black from
playing Bg4 pinning the Knight to the Queen. In many main line
variations for example the Chigorin and Breyer variations, White
doesn't play h3 until 2 moves after Black's ... d6 (playing c3 first),
but Black castles instead of playing … Bg4. My questions then are :
What exactly is the purpose of White's h3 in the Ruy Lopez? Why is this
weakening of the pawns in front of the King not a problem for White?
Why does white need to play c3 first? Finally, why must Black castle
before playing Bg4?

Joe Freiberg

Joe,

It is well known that pawn moves in front of the king must be considered for the potential danger to the king position. Sometimes the pawns can be a target for a pawn storm. Sometimes the chances for a sacrifice may be increased. Sometimes light or dark squares may be compromised. But most authorities would agree that more often than not, h2-h3 (or h7-h6 for Black) is a positive move. It prevents pins from occurring and, as all my schoolchildren know, creates air for the king to eliminate back rank checkmates. So if there is no apparent reason in a given position why h2-h3 should be weakening, don't be afraid to play it.

Your question about the Ruy Lopez is quite instructive for a good number of players. There are actually specific reasons why the moves are played in a particular order.

White plays 8.c3 here from a combination of "need" and "want." He wants to prepare d2-d4 staking out a claim to the center. He needs to play c2-c3 now because Black has created a positional threat by defending the e5-pawn. If White plays 9.h3, Black will grab the bishop pair with 9…Na5! Moreover, White does not need to play 9.h3 because 9…Bg4 isn't a threat.

After 8.c3 0–0 White has traditionally preferred 9.h3 to 9.d4. Though 9.d4 is a perfectly good move which has been somewhat fashionable lately, the reply 9…Bg4 puts White's center under immediate pressure.

You are quite right to wonder why if Bg4 is such a good answer to 9.d4, why not play it a move earlier to keep White from playing d4 at all?

Higher rated players are hesitant to commit their bishop to g4 because the bishop is likely to be misplaced on g4 if White doesn't play d2-d4. After 8…Bg4 9.d3! 0-0 10.h3 Bh5 11.Nbd2 White will continue with the maneuver Nd2-f1 to g3, breaking the pin. Black will either have to surrender the bishop pair or see the bishop buried on g6.

There is actually a similar line that works a little better for Black: 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.0–0 Be7 6.Re1 d6 7.c3 Bg4!?

By the way, that last move is indeed a pawn move around the potential home of Black's king. It's safe because Black has the dark squares well covered (he has a bishop in the area, while White has traded his dark bishop). It's logical because it restricts the movement of White's knight.